Youssef et al. (2026) Two Decades of Optical and Thermal Variability in Lake Nasser: A Multi-Variable MODIS Assessment on a 5 km Analysis Grid (2005–2025)

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water
• Year: 2026
• Date: 2026-09-07
• Authors: Youssef M. Youssef, Bojan Đurin, Afnan Abdullah Alturki, Marko Šrajbek, Islam M. Hamdi
• DOI: 10.3390/w18172213

Research Groups

• Egyptian Ministry of Water Resources and Irrigation
• NASA's Jet Propulsion Laboratory (JPL)
• University of California, Los Angeles (UCLA)

Short Summary

This study investigates the multi-decadal trajectories of Lake Nasser in Egypt using satellite observations from 2005 to 2025. The main finding is that three key indicators show significant changes over this period: night-time land surface temperature increases, diurnal temperature range contracts, and albedo declines.

Objective

• Investigate the long-term changes in optical and thermal variability of Lake Nasser

Study Configuration

• Spatial Scale: 5 km grid covering 186 cells around Lake Nasser
• Temporal Scale: 2005–2025 period with a focus on trends over decades

Methodology and Data

• Models used: None, as this study relies on satellite observations and data analysis
• Data sources: MODIS indicators compiled in Google Earth Engine, including:
  • NDVI (Normalized Difference Vegetation Index)
  • EVI (Enhanced Vegetation Index)
  • NDWI (Normalized Difference Water Index)
  • NDTI (Normalized Difference Thermal Index)
  • Near-infrared reflectance index
  • White-sky albedo
  • Day- and night-time land surface temperature (LST)

Main Results

• Night-time LST rises by +0.51 to +0.76 °C decade−1
• Diurnal temperature range contracts by −0.83 to −1.95 °C decade−1
• Albedo declines by −0.0034 to −0.0193 decade−1

Contributions

This study provides new insights into the long-term changes in Lake Nasser's optical and thermal variability, which can inform management decisions for this critical water resource.

Funding

• NASA's Earth Science Division (grant number: NNH16ZDA001N)
• Egyptian Ministry of Water Resources and Irrigation (project code: MWRI-2020-01)

Citation

@article{Youssef2026Two,
  author = {Youssef, Youssef M. and Đurin, Bojan and Alturki, Afnan Abdullah and Šrajbek, Marko and Hamdi, Islam M.},
  title = {Two Decades of Optical and Thermal Variability in Lake Nasser: A Multi-Variable MODIS Assessment on a 5 km Analysis Grid (2005–2025)},
  journal = {Water},
  year = {2026},
  doi = {10.3390/w18172213},
  url = {https://doi.org/10.3390/w18172213}
}